Problem: Evaluate the following expression when $d = 6$ and $c = 8$. $8$ $d$ $ + 8$ $c$ $ - 4$
Solution: Substitute $6$ for ${d}$ and $8$ for ${c}$ $ = 8{(6)} + 8{(8)} - 4 $ $ = 48 + 64 - 4 $ $ = 108$